Dental chair



Sein. 1, 1925.

1,551,730 F. E. cAsE DENTAL CHAIR Onzin Filed Aug. 50, 1922 2Sheets-Sheet 1 Sept. 1, 1925. 1,551,730

|` E. cAsE DENTAL CHAIR Original Filed Aug. 30, 1922 `2 Sheets-sheet 2vweutoz ihm/KE. Case.

Patented Sept. l, i925,

UNITED STATES PATENT OFFICE.

FRANK E. CASE, 0F CANTON, OHIO, ASSGNOR TO THE HARVARD COMPANY, OF CAN-TON, OHIO, A CORPORATION 0F 0HIO.-

Y v I 'DENTAL CHAIR.

Original application filed August V30,

To all whom t may concern.'

Be it known that I, FRANK E. CASE, a citizen of the United States, tresiding at Canton, Vin the county of Starkand State of Ohio, haveinvented certain new Vand usev ful Improvements yin 'Dental Chairs, of

4which the followingis a specification.

The invention relates to dental chairs and the like, in which Athe backsupport is slidably fulcrumed onthe seat frame for swingy provideclamping means for sustaining and securing the back support in thevarious'positionsinto which it may be swung.

' Dental chairs may havethe back support slidably fulcrumed to the seatsupport by means of anarcuatej guide on the'one and an arcuateslide on Ithe other; and kthe weight of the back support and 'head rest togetherwith the weight of a reclining patient is so considerable, thatdifficulty is experienced in 4securing and holding the arcuate slide 1na fixed position upon the arcuate guide.

. `To avoid'thisdiliiculty, the present invention involves the use of aclamping plate for sliding circumferentially Vupon the 'seat guide, atansverse wedge block adjustable laterally in the back-support, and aninter-Y vening roller impinging diverging `faces of the plate and blockwith yielding means normally holdingv the parts in clamped contact andmanual meansv for moving the plate and roller for'releasing the clampingconf tact.

The improvement is illustrated in the accompanying drawings forming'part hereof, invwhichf Figurel is a fragmentary side elevation sectionin the median 'line of the arcuate guide and slide connection betweenthe seaty frame and the back su'pport,showing the roller wedge clampingmeans therein;

Fig. 2, a section of the same looking up-- ward on the line 2 2, Fig. 1

Figf, ar detached perspective 'view of the clamping plate;k

F ig. 4, a detached perspective view of the clamping roller;

1922, Serial No. 585,315. Divided and this application l24, 1923. SerialNo. 682,554,v n

led December Fig. 5, a detached wedge block; l y

Fig. 6, an enlarged longitudinal section of the clamping members on theline 6 6, Fig. 2.; and f Fig. 7, a fragmentary perspective view of aportion of a seat frame and back supporft. -W 1 Similar numerals referto similar parts throughout the drawings. f

An arcuate guide plate 1 is secured to the rear end of the seat frame 2as by means of rivets 3 and 3, the rear face of which plate is curvedupon a transverse axis 1 located above therear end of the seait frame,and the edges 1f of the `plate serveas guides which perspectiveview ofthe `are engaged in arcuate grooves 4 in the vgitudinal convex curve oftherrear kface of the arcuate guide l, so that the clamping plate willlit and slide longitudinally there-v on. i l

The rear faceI 6.of the clamping plate is preferably formed in a flatplane, to give the body a wedging` thickness tapering from a thinnerupper end to a thicker lower end;

and the Arear Y face is also provided with n. flangesa onthe edges,`which form a guide for the ends ofthe clamping rollerk 8.

The clamping plateG is normally urged Y upward for a clamping`connection by av rcoiled compression spring 9 aligned between a guidepin 9" and a surrounding abutment in the wall of the back support, and aguide pin 9 and a surrounding abutment on the lower end'of the clampingplate; and the clamping plate may be manuallymoved upward and `downwardby means of a hand lever 10 secured by a pivotal bolt l0 on the blacksupport, `and a connecting bar l1v eX- tending downward from a pivotalconnection with the lever along a groove 12 in the i forward face of theback support, to a pivotal connection with the upper end of the clampingplate.

The rear yside 13 of the wedge block 7 is transversely inclined andconvexly curved to .ride in the transverselyA inclined straight bottomof the channel 14 lformedv in the wall of the back support; and atransverse rib 13 likewise laterally inclined and convexly curved ispreferably provided in the median line ofthe block to ride in the bottomof a similarly inclined, straight groove 1st provided in the bottom ofthe channel for holding `the block inf true lateral. alignment, whilepermitting it to rock sidewise'so as to exactly accommodate itself to .alongitudinal bearing upon the clamping roller 8.

The forward face 7 of the wedge is formedflat in its middle portion, andthe flat face is positioned in a downwardly diverging vangle from therear face 6 of the clampingplate to an increasing divergence as the sameis moved downward, and is provided with flanges 15 and 15 on its upperand lower edges to form stops for the clamping roller 8 which is locatedand operates between the .diverging inclined fiat faces of the clampingblock and the clamping plate.

lA. transversely positioned set screw 1G in the side wall of the backsupport abuts the thicker end of the wedge block T and by a turningofthe screw, the wedge .can be adjusted sidewise so as to give .thenecessary clamping action for locking` thearcuate guide and slidetogether, as follows:

The parts are soV proportioned that when the clamping plate 6' is urgedupward by the compression Ispring 9, or by an operation of the handlever 10 the roller 8 will be wedged between the inclined faces of theplate-and block `so as to clamp the arcuate slide uponthe arcuate guide,as shown vin Fig. lfbut bymoving the` plate downward by operation of thehand lever 10, the roller will be carried downward between the divergingfaces of the plateand block, so as to release the clamping action of thesame and permit the arcuate slide to freely move upon the arcuate guideuntil a desired adjustment is'attained', whereupon either lor both areverse movement of the hand lever and operation of the compressionspring,

moves the clamping plate upward and again locks the parts rigidly in thegiven position of adjustment.

It is evident that the lateral rocking vof the wedge block permitted bythe transversely inclinedconvexity of its back, serves to seat the sameat all times against the roller, and that by an adjustment of the setscrew 16, all looseness Afrom wear or otherwise, can be readily takenup, so that the roller will always act to rigidly clamp -the oint in'any given position of adjustment when the clamping plate is movedupward, either by the compression spring or the hand lever.

1. Clamping means between the arcuate 'guide and the arcuate slideconnecting the seat and the backof a dental chair or the like, includinga plate having an arcuate face sliding on the arcuate guide, a blockbearing in the slide with its presented face downwardly diverging fromthe opposing face of the plate, and a roller between the plate and theblock for wedge clamping the parts by an upward movement of the plate.

2. Clamping means between the arcuate guide and the arcuate slideconnecting the seat and the back of a dental chair `or the like,including kka plate having an arcuate face sliding on the arcuate guideand an opposite face downwardly diverging therefrom, a laterallytiltingvblock bearing in the slide with its presented face downwardlydiverging from the diverging face of the plate, and a roller between theplate and the block for wedge clamping the parts by an upward movementof the plate.

3. Clamping means-between the arcuate guide and the arcuate slideconnecting the seat and the back of a dental chair or the like,including a plate having an arcuate face sliding on the arcuate guide, alaterally tilting block bearing in the slide with its presented facedownwardly diverging from the opposing face of the plate, -a rollerbetween the plate and the block, and means for urging the plateupwal'dfor clamping the parts together.

el. Clamping means between the arcuate' guide and the arcuate slideconnecting the seat and the back of a dental chair or the like,including a plate having an arcuate face sliding on the arcuate guide, alaterally tilting block bearing in the slide with its presented facedownwardly diverging from the opposing face of the plate, a rollerbetween the plate and the block, and yielding Ameans for urging theplate upward for `clamping the parts together.

5. Clamping means between the arcuate guide and the arcuate slideconnecting the seat and back of a dental chair or the like,

vincluding a plate having an arcuate face sliding on the arcuate guide,a laterally adjustable wedge block bearing in the slide with itspresented face downwardly diverging from the opposing face of the plate,and a roller between the plate and the block for vwedge clamping theparts by an upward movement of the plate.

6. Clamping means between the arcuate guide and the arcuate slideconnecting the seat and the back of a dental chair or the like,including a plate having an arcuate face sliding on the arcuate guidewith edge flanges on its opposite sides, a block bearing in the slidewith its presented face downwardly dverging from the opposite face ofthe plate,- and a roller between the plate and the block for wedgeclamping the parts by an upward movement of the plate.

7. Clamping means between the arcuate guide and the arcuate slideconnecting the seat and the back of a dental chair or the like,including a plate having an arcuate 10 face sliding on the arcuategude,' a block` bearing in the slide with its presented face downwardlydivergng from the opposite face of the plate and having stop flanges onkits upper and lower edges7 and a roller between the plate and the blockfor wedgeL clamping the of theV plate.

In testimony that I claim the above, I have hereunto subscribed my name.Y

` FRANK E. CASE.

partsby an upward movement

